Direct Light cache: how to avoid splotches?

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marcatore
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Re: Direct Light cache: how to avoid splotches?

Post by marcatore » Fri Dec 21, 2018 12:00 pm

I've tried the last beta4 but it seems it's not solving the problem.

I'm with default settings and I have this
blender_2018-12-21_12-36-50.png
The issue with the curtain is solved...it seems it remains the fur as unsolved

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Dade
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Re: Direct Light cache: how to avoid splotches?

Post by Dade » Fri Dec 21, 2018 2:03 pm

Are you using an AMD GPU ? Have you tried with CPU rendering ?

Sharlybg had found some bug in some AMD specific driver version when using DLSC and AMD GPU (it works fine with CPU and NVIDIA so it is very likely to be an AMD driver bug).
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marcatore
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Re: Direct Light cache: how to avoid splotches?

Post by marcatore » Fri Dec 21, 2018 3:21 pm

No, Nvidia Quadro K5200 + Intel Xeon E5-1650 @3,50ghz

I'll try only CPU

marcatore
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Re: Direct Light cache: how to avoid splotches?

Post by marcatore » Fri Dec 21, 2018 3:33 pm

This is a CPU test
blender_2018-12-21_16-31-17.png

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Dade
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Re: Direct Light cache: how to avoid splotches?

Post by Dade » Sun Dec 23, 2018 3:43 pm

I was using a DLSC warmup samples value of 128-256 in my tests, can you try ?
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lacilaci
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Re: Direct Light cache: how to avoid splotches?

Post by lacilaci » Sun Dec 23, 2018 4:00 pm

Dade wrote:
Sun Dec 23, 2018 3:43 pm
I was using a DLSC warmup samples value of 128-256 in my tests, can you try ?
A little OT... I'm trying to use lightcache in my interior scene. But I'm getting very, very long computation times for DLCS (34 537, light sources) unless I use very low samples count and precission %, which introduces a lot of splotching.
Is there some plan to make this process faster, like a LOT faster cause I'd rather wait extra time for rendering without the feature atm...

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Dade
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Re: Direct Light cache: how to avoid splotches?

Post by Dade » Sun Dec 23, 2018 10:16 pm

lacilaci wrote:
Sun Dec 23, 2018 4:00 pm
Dade wrote:
Sun Dec 23, 2018 3:43 pm
I was using a DLSC warmup samples value of 128-256 in my tests, can you try ?
A little OT... I'm trying to use lightcache in my interior scene. But I'm getting very, very long computation times for DLCS (34 537, light sources) unless I use very low samples count and precission %, which introduces a lot of splotching.
Is there some plan to make this process faster, like a LOT faster cause I'd rather wait extra time for rendering without the feature atm...
If someone find a way. But what type of light sources are you using for the 34,537 ? I assume area lights, are they in a single mesh or multiple and if multiple how many for each mesh ?
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lacilaci
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Re: Direct Light cache: how to avoid splotches?

Post by lacilaci » Sun Dec 23, 2018 10:32 pm

Dade wrote:
Sun Dec 23, 2018 10:16 pm
lacilaci wrote:
Sun Dec 23, 2018 4:00 pm
Dade wrote:
Sun Dec 23, 2018 3:43 pm
I was using a DLSC warmup samples value of 128-256 in my tests, can you try ?
A little OT... I'm trying to use lightcache in my interior scene. But I'm getting very, very long computation times for DLCS (34 537, light sources) unless I use very low samples count and precission %, which introduces a lot of splotching.
Is there some plan to make this process faster, like a LOT faster cause I'd rather wait extra time for rendering without the feature atm...
If someone find a way. But what type of light sources are you using for the 34,537 ? I assume area lights, are they in a single mesh or multiple and if multiple how many for each mesh ?
It's multiple dense meshes, I disabled on many of them DLS, but I guess cache is still computed...?

I have no idea how this works, but maybe if light sources could be treated as a "group" if they are part of single object and if cache could be calculated per "group"/ object then, so that there isn't overkill amount of cache entries from small hi-poly sources.

Or just give the ability to turn caching off for emission material. So that unimportant small sources don't slow caching process...

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lacilaci
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Re: Direct Light cache: how to avoid splotches?

Post by lacilaci » Mon Dec 24, 2018 8:18 am

If you think about it, you will have to eventualy make it possible to disable caching per light.
Because idealy user would create "fake hipoly source no dls" and hidden lowpoly actual source(needs the ray visibility feature first) then only calculate dls and cache for the hidden source.
This way, fast caching and many light sources can happen.
Well, unless someone finds a way to dramaticaly speed up caching itself.

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Dade
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Re: Direct Light cache: how to avoid splotches?

Post by Dade » Mon Dec 24, 2018 6:49 pm

Direct light sampling (and cache computation) is automatically disabled for meshes with more than X triangles (it should be something like 256 but I can not check at the moment).
It should be your case or are you using a lot of small meshes ?
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